1. Field of the Invention
The present invention relates to a data distribution processing system, data distribution processing method, and program which split data into data blocks and distribute the data blocks to a plurality of devices connected to a network and then collect the data blocks to reconstruct the original data.
2. Description of the Related Art
With increases in functionality of copiers, recent copiers are equipped with a storage device such as a hard disk to temporarily hold images read by scanning paper documents and the like. Furthermore, the copiers are provided with networking functions to exchange data held in respective storage devices among themselves by being connected via a network.
An example of data exchange will be described by citing a system in which a plurality of copiers 201 to 210 are placed on a network 213 such as shown FIG. 2A. Generally, a document (original) scanned by copier A (201) is printed out by copier A (201).
A storage device such as a hard disk of a copier is used, for example, as follows. A document is scanned by copier A (201) and resulting image data 214 is stored on a hard disk or other storage device 211 of copier A (201). The image data 214 is acquired from the storage device 211 of copier A (201) by copier B (210) connected to the network 213. The acquired image data 214 is printed out by copier B (210).
Alternatively, when copier A (201) scans a document, the image data 214 read into the storage device 211 of copier A (201) may be transferred to a hard disk or other storage device 212 of copier B (210). In that case, copier B (210) produces printouts using the image data transferred and stored in the storage device 212.
It is assumed naturally that the copiers 201 to 210 perform appropriate authentication processes. Also, it is assumed that the copiers 201 to 210 are capable of identifying the image data stored in the storage device 211 or 212.
Due to increased security awareness, many companies and the like forbid taking notebook PCs, USB memories, or other external memories out of the companies or the like. Consequently, chances are increasing that documents (originals) scanned by a copier are outputted via an external network to which the copier is connected.
In view of this, security is enhanced by encrypting the data transferred between copiers.
Also, a method is known in which scanned images are stored in a distributed manner among storage devices of copiers connected to a network (see for example, Japanese Patent Laid-Open No. 2004-118239).
However, simple encryption of the data transferred between copiers is not enough to prevent malicious third parties from intercepting the data even if the entire data is encrypted. Also, encryption may be broken by advanced computer technologies or the like. Besides, since the entire data flows through the network, all the data may leak once it is deciphered.
The method described in the patent document above enhances security by managing data in a distributed manner. However, the method assumes that the data is restored on the scanning copier and it does not allow for secure output from other copiers and similar devices on the network.